This is a very short video we produced explaining the use of alum to clarify silty river water. I’m wondering if it would have the same effect on tannin and organics in our northern lakes. Darn, I’m going to have to make a trip and find out! 
http://www.youtube.com/watch?v=jv-5yJXpUy0&feature=share&list=UUPTRxvim0f_Pm_7wjbArkgg
I dislike the taste it gives
Used it on the Green and Missouri last month. We had just as good results from overnight settling and filtering.
alum
We too, as a possible alternative, tried the overnight settling without the alum. We found that there was a considerable amount of sediment that just wasn’t heavy enough to fall to the bottom, even after this long period of time. Our conclusion was that it would clog our filter and wasn’t a viable procedure, for us anyways.
There is a little taste to the alum. We pass our water through a charcoal filter at the end. This takes the majority of it out, enough to make it very palatable. Maybe you put too much alum in, it doesn’t take much.
When you find a method that makes river water taste like Perrier please let me know.
Well I would like to know too
but our gravity filter is easy to backflush. On the Green we filtered every day… Two trips now for two weeks. As backflushing is so easy it was OK as a daily preventative measure.
Personally I hate Perrier . Nestle bottles and sells my home aquifer water, which is quite good. Any water from “away” pales in comparison.